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Despite the rise in published evidence of deep‐marine bottom current processes and associated deposits there are still very few documented outcrop examples. Herein are reported results of a contourite channel system related to the late Miocene palaeo‐Mediterranean Outflow Water in the Rifian Corridor, Morocco. This work aims to unravel the sedimentary evolution and facies distribution based on the study of large morphological features related to contourite channels and their subsequent sandstone dominated infill sequences. It was found that the channel evolution and facies distribution are related to spatiotemporal changes in flow characteristics of the palaeo‐Mediterranean Outflow Water. The recognized channel facies distribution correlates well with previously established bedform stability diagrams. Erosion and upper‐stage flow regime bedforms are associated with the most vigorous bottom currents, generally related to its core. Laterally, following the decrease in flow velocity towards the adjacent drift, bedforms comprise dunes, lower‐stage plane bedforms and more heterolithic facies. Similar facies changes are also observed down‐channel, related to a decrease in flow velocities resulting from turbulent mixing of water masses, associated decreases in density gradients and the subsequent deceleration due to gravity. Results of this work have been used to propose a three‐dimensional facies model for channelized sandy contourites. This study contributes to understanding contourite systems, thus benefitting oceanographic and climatic reconstructions as well as aiding the predictability of contourite channel systems for industry geoscience applications. [ABSTRACT FROM AUTHOR]

The term base-of-scarp is proposed for those submarine deposits controlled by a fault and physically disconnected from their more proximal counterpart located on the footwall, although genetically linked to it. These systems differ from conventional fault-controlled deltas, such as shoal- and Gilbert-type, because they are entirely subaqueous and lack equilibrium morphology--a steady state in which the system grows in size without altering its shape. We present field examples of fault-controlled deposits from the Crati Basin and the Messina Strait (southern Italy) consisting of stratigraphic clastic wedges that thin towards and onlap onto the active margin with primary inclined bedding. Beds are composed of immature coarse-grained gravels and sand, lack structures representative of wave-action and reflect gravity-driven processes such as debris flow, debris fall and high-density turbidity currents. These deposits represent the unsteady-state phase in which the system grows reducing its slope angle leading to conditions under which the unsteady state may eventually turn into a Gilbert-type or shoal-water system. A diagram for fault-controlled baseof-scarp (B), Gilbert (G) and shoal-water (S) deposits is presented, including their steady- and unsteady states, and the conceptual conditions under which a base-ofscarp system might evolve into Gilbert-type or shoal-water systems and vice versa. [ABSTRACT FROM AUTHOR]

Plastic pollution is widespread throughout the marine environment representing a risk for ecosystems and human health when plastic enters the food chain. Understanding factors and processes controlling plastic distribution and accumulation is crucial to identify plastic hotspots. Gateways and straits can play an important role on transferring plastic debris at superficial and sea bottom level depending on the local water masses stratification. [ABSTRACT FROM AUTHOR]

Interbedded contourites, turbidites and pelagites are commonplace in many deep‐water slope environments. However, the distinction between these different facies remains a source of controversy. This detailed study of calcareous contourites and associated deep‐marine facies from an Eocene–Miocene sedimentary succession on Cyprus clearly documents the diagnostic value of microfacies in this debate. In particular, the variability of archetypical bi‐gradational contourite sequences and their internal subdivision (bedding, layering and lamination) are explored. Contourites can be distinguished from turbidites, pelagites and hemipelagites by means of carbonate microfacies in combination with bed‐scale characteristics. Particle composition provides valuable information on sediment provenance. Depositional texture, determined by the ratio between carbonate mud and bioclasts, is crucial for identifying bi‐gradational sequences in both muddy and sandy contourites, and normally‐graded sequences in turbidite beds. Equally important are the type and preservation of traction structures, as well as the temporality and impact of bioturbation. Shell fragmentation under conditions of increased hydrodynamic agitation (textural inversion) is recognized as a carbonate‐specific feature of bioclastic sandy contourites. [ABSTRACT FROM AUTHOR]

Clinoform surfaces are routinely used to mark transitions from shallow waters to deep basins. This concept represents a valuable tool for screening potential reservoir intervals in frontier basins where limited data are available. Variations in the character of clinoform geometries and shoreline and shelf-edge trajectories are indicators of a range of different factors, such as palaeobathymetry, changes in relative sea-level and sediment supply. Applications of conceptual and generalized models might, however, lead to erroneous assumptions about the supply of coarse-grained material to the delta front and basin when superficial similarities between clinoform geometries are not treated holistically. The present study examines the mudstone-dominated Middle Triassic Kobbe Formation - a potential hydrocarbon reservoir interval in the Barents Sea, where prodeltaic to deltaic deposits can be examined in cores, well logs and two-dimensional and three-dimensional seismic data. Despite pronounced acoustic impedance contrast to the surrounding shale, channel belt networks are not observed close to the platform edge in seismic datasets, even at maximum regressive stages. However, sub-seismic prodeltaic deposits observed on the shallow platform indicate that prodeltaic deposits were sourced directly from the delta plain. Clinoform surfaces with different geometries and scale are observed basinward of the palaeoplatform edge of underlying progradational sequences, correlative to mudstone-dominated prodeltaic core sections. Results indicate that platform-edge deltas developed at discrete sites in the basin due to normal regression, but the positions of these deltas are not directly relatable to variations in clinoform geometries. Transitions from third-order to fourth-order clinoform geometries record discrete transgressive-regressive cycles but are not necessarily good indicators of sandstone deposition. Because of prolonged periods with high accommodation, channel avulsions were frequent and only very fine-grained sandstone was deposited in heterolithic units at the delta front. Sandstones with good reservoir properties are predominantly found along basin margins. [ABSTRACT FROM AUTHOR]

In this work, we apply digital rock physics (DRP) to characterise the pore geometries of the Brae Formation sandstones. Core plugs used for image acquisition, subsampled from standard ~15 cm wide core to 5mm diameter plugs, pertain to two different wells located in the Brae-Miller fields complex (North Sea, UK). Using micro-CT scans at two resolutions, we calculate the porosity, permeability and generate pore network models to assess pore shape characteristics and heterogeneity. The images are filtered and segmented to separate the porosity from grain/matrix. The pore space images are then further processed to calculate the proportion of effective porosity before pore network modelling and the simulation of absolute permeability. The samples display a range in total porosities from 5% to 15% with the connected proportions of the pore space showing only a slight decrease. Pore network model results indicate that the samples have median pore and throat radii ranging from 6 um to 17 um and 6 um to 13 um respectively. The throat length of all samples has a median value ranging between 36 um and 82 um. Absolute permeability simulations highlight that there is anisotropic permeability in all samples. [ABSTRACT FROM AUTHOR]